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Finding the Fourth Proportional to 668.14, 921.90 and 388.38

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Solution

The fourth proportional to 668.14, 921.90 and 388.38 is: 535.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.14 : 921.90 = 388.38 : x
  2. Step 2: Convert to fraction form
    668.14/921.90 = 388.38/x
  3. Step 3: Cross multiply
    668.14x = 921.90 × 388.38
  4. Step 4: Simplify right side
    668.14x = 358,047.52
  5. Step 5: Solve for x
    x = 358,047.52/668.14
  6. Step 6: Final answer
    x = 535.89

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.